The present invention generally relates to apparatus and methods for ozone (O3) sterilization of medical equipment and more particularly, to apparatus and methods for ozone sterilization of medical equipment using a centralized controller and other devices to control and perform sterilization of the instruments housed in multiple chambers, each of relatively compact size.
Ozone sterilization of medical equipment is typically performed by preparing the medical equipment with water vapor, which increases the effectiveness of a later exposure to ozone. To improve the effectiveness and shorten the time of the ozone sterilization, each step of the process is preceded by removing the internal atmosphere in the sterilization chamber by creating a vacuum inside the chamber thus ensuring the penetration of the next step's atmosphere into and around the medical equipment to be sterilized. Accordingly, an ozone sterilization cycle requires removing the air from the chamber, pumping steam into the chamber, pumping ozone into the chamber, allowing the sterilization process to run its course and then pumping out the contents of the chamber before pumping in clean air.
Accordingly, the process requires, among other things, a chamber large enough to house the medical instruments, an ozone generator (ozonator) strong enough to generate ozone for the large chamber, and a pump for air removal strong enough for the large chamber. Larger chambers, for example a 100 liter chamber, require larger peripheral service devices. The larger peripheral service devices (e.g. pumps and ozonators) tend to be not just larger in size but also more sophisticated and hence significantly more expensive. In addition, production costs for producing the larger chambers rise faster than linearly in proportional to the size of the chamber.
Medical equipment comes in many shapes and sizes, including long tubular instruments such as catheters and endoscopes. Different medical instruments, based on their structure and type of material, require different sterilization programs. For example, hollow, elongated medical instruments closed on one end may require repetition of a vacuum, steam, and ozone cycle one or more times to ensure proper penetration of ozone throughout the depth of the inside of the medical instrument, including in hard to access areas.
The typical overall time for ozone sterilization is 20-30 minutes. Accordingly, since some instruments require cycle repetition, the pump may have to achieve a required level (i.e. 3 to 6 millibars) in less than 5 minutes and preferably 3 minutes. In addition, the time to introduce ozone into the chamber may have to be 3 minutes or less to leave enough time for the entire sterilization cycle.
There is an ongoing need for improved methods and devices for ozone sterilization that are cost effective, efficient and suitable for all types of medical equipment.